The present invention relates to a method of beating fibre slurries, such as paper-pulp suspensions, and lump-goods, such as wood-chips and wood-shavings. The invention also relates to a beater for use in carrying out the method.
When manufacturing paper-pulp, it is necessary to beat the cellulose fibres in order that sufficient bonds are obtained in the lattice-structure between the various fibres in the resultant paper sheet. These bonds comprise hydrogen bonds between the molecular chains, and are mainly formed when the paper is de-watered and dried.
In the conventional beating of fibre slurries on a factory scale, changes are produced in the fibre structure, of which changes some are desirable while others result in negative side effects. In order to obtain a good binding ability, it is desirable that the primary wall and partly also the outer secondary wall of the fibre are peeled or stripped off, and that the internal hydrogen bonds are broken and replaced by hydrogen bonds between the fibre and the water. In this way the fibre is delaminated, takes up water, swells and becomes flexible. Further, external disintegration or loosening of the fibre wall is desired, which permits external fibrillation and foliation. In the majority of cases, however, the excessive crushing and cutting of the fibres obtained when using conventional beating or refining apparatus, is undesirable. In such conventional refining apparatus, the fibre material is worked mechanically against the edges and other surfaces of the beating means.
Thus, the main object of the present invention is to provide a method and a beating or refining apparatus with which the aforementioned disadvantages are eliminated and in which fibres are treated in a manner such as to break the internal hydrogen bonds of said fibres without clipping or crushing the same, said fibres being capable of absorbing water and swelling and becoming flexible.